On Thursday, Los Angeles police plumbed the oily waters hoping that some evidence in a homicide investigation would bubble up to the surface.

Officer Rosario Herrera says a dive team searched the black lagoon in the heart of the city's Miracle Mile area. Police won't say if anything was found, or exactly what they were looking for.

Sgt. David Mascarenas has been a police diver for 16 years but said he has never been in a situation as strange as Thursday's dive, when he could barely see past his mask and twice got stuck the in gelatinous tar.

"I've been under moving ships, in underwater reservoir sheds and I've been lowered into dams, beside piers, in pipelines and swimming pools, you name it," Mascarenas told the Los Angeles Times. "This is by far the craziest thing I've ever done."

The La Brea Tar Pits are located on Wilshire Boulevard, on the same campus as the Page Museum and the Los Angeles County Museum of Art.

Hundreds of thousands of animal carcasses have been dredged from the tar pits through excavations over the last century, helping scientists piece together the long-ago inhabitants of the Los Angeles Basin.